A front fork for supporting a front wheel of a motor-cycle comprises, for example, a fluid pressure shock absorber comprising an outer tube, an inner tube fitted into the outer tube, a cylinder disposed in the inner tube, and a piston accommodated in the cylinder and supported by the outer tube via a piston rod to be free to slide in the cylinder.
JP2008-69830A, issued by the Japan Patent Office in 2008, proposes a fluid pressure shock absorber in which a head member that supports the piston rod to be free to slide is screwed onto a tip of the cylinder. An outer circumference of the head member is caused to contact an inner circumference of the inner tube, and as a result, the head member functions to maintain concentricity between the cylinder and the inner tube.